All In Your Head
by SparkleRightsSmut
Summary: Right now, thanks to their meta of the week, Barry has absolutely zero time to himself and it's starting to rub him the wrong way. - Barry and Frost end up sharing a body and his speedster appetite for regular sex makes itself known.
1. Chapter 1

Hearts to thestarkswillendure for looking this over.

Tags/warnings - Plot What Plot/Porn Without Plot, Unresolved Sexual Tension, Sharing a Body, Masturbation, Speedster Sex, Bisexual Barry Allen, POV Barry Allen, Horny Barry Allen, Dirty Talk, Barry Allen is single here, Maybe more to come, pun intended, (Minor Barry Allen/Cisco Ramon, very very minor UST, just a passing thought)

-**All In Your Head-**

There are plenty of upsides to being a speedster. Barry enjoys _everything_ about it – the buzz of the Speedforce practically electrifying every cell in his body; the thrill of the chase running for the sake of it even when he doesn't have to. The increased appetites of a speedster are one of the major potential downsides. They don't _have_ to be. They _can_ be extremely pleasurable too, provided they don't slip into becoming a chore, and he's got access to what he needs; plenty of food and time to himself.

Right now, thanks to their meta of the week, Barry has absolutely zero time to himself and it's starting to rub him the wrong way.

Because there is _no_ rubbing of any kind going on.

With each movement he itches to touch himself, his brain working on overdrive to tempt him with the idea of palming himself there in the cortex with no mind to anyone walking in. Naturally, he doesn't.

It's been 36 hours, which might as well be a lifetime for a speedster. He could practically burst. So much of his willpower is going on self-control. It's hard for him to focus on a conversation, much less figuring out a solution to this powerswap. If you could call it that – really he's doubled up on powers. Turns out speedster powers and the icy kind don't mix well. He's still got the same metabolism but so far any attempt to tap into the Speedforce borders on agonizing. That itself isn't the main problem he has though.

_Hey, doofus, I can feel what you feel. I __**know**__ you're horny as hell._

"What? No!" Barry stops himself from gaping, flushing red at her words. "Don't you have _any_ boundaries?"

_**I'm **__stuck here, that's not changing anytime soon. You do you, by doing you._

He can practically hear Frost's smirk as she torments him with the joke _and_ the suggestion. She's not wrong. Normally her and Caitlin can tune out what's going on if they choose. Barry has no clue how he'd do that and Frost insists that isn't possible while she inhabits Barry's foreign brain. There's nowhere for Frost to retreat to. Which means there is no privacy for either of them.

"We're not having this conversation," he says, resolute to shut this down before it gets anymore out of hand. He wants to do what she's saying - at least it's good to know she consents - but it's just too weird. Wrong. He needs to get her to stop talking about it because he can't deal with the lust that threatens to overwhelm him every time she pushes further about it.

_Come on,_Frost says in his head, much too sultry about it, _I've always wanted to know what having a dick would feel like, don't leave me hanging._

"Frost!" he practically growls in warning.

_What do I have to say, Flash - pretty please with a handjob on top?_

He takes a deep breath and endeavors to ignore her. Fat chance of that, Frost is every bit as stubborn as her human counterpart and with much less tact.

Caitlin comes in about the same time he starts loudly going "La la la la la la" to try to drown out Frost's incessant commentary.

"Are you okay?" Caitlin asks, a tone of light concern in her question, "Is Frost bothering you?"

Frost's retort that only he can hear is quick to come. _We could get Caity to help you out, would that make it less weird?_

He stifles a groan at the image that pops up, desperately pushing down the half-formed fantasy at Frost's words.

"You could say that," he replies to Caitlin, curter than he'd normally be.

"Give him a break, Frost," Caitlin demands with a semi-stern look thrown his way for her benefit.

_I could give you a whole lot more. You could sit back and let me do all the work. I'd figure it out. Can't be that hard, for long._

Barry swallows hard, feeling ever more uncomfortable with how he's filling out his pants. Resisting the urge to adjust himself and draw attention to his situation, he keeps things simple with his answer.

"Thanks, Cait. Gonna work on this some more."

Irritatingly, he can't even Flash out of there to cover up his hard-on. Opposing powers of hot and cold don't play nice together. Caitlin exits innocently enough but he has to studiously not watch her walk away lest it inspires thoughts he can't let creep into his mind.

_You don't have any work you __**have**__ to do. You're not going to solve anything this wound up, genius. If you're worrying your handsome lil' head about being overheard we could just go home and jack off already. This is torture for me too you know._

He can't stand being around people like this any more. He gets his infrequently used Uber app up on his phone and orders a car home. The offered discount code for bringing his business back is a tiny, momentary everyday distraction as he books it. The distraction doesn't last.

_Finally! _Frost's throaty exclamation sounds as desperate as he feels.

As he passes the time until the car arrives, he has to fight so hard to not just buck up into his hand to get some relief. Barry alternates between clenching his fists tightly or idly typing, feigning productiveness. Cisco passes by and witnesses his slightly too harsh abuse of the equipment in his frustration.

"What did that keyboard ever do to you?" is what Cisco says and Barry _does_ hear it. He also hears the obscene slurp of Cisco removing the sucker from his mouth that precedes it and he definitely gapes this time.

"Whatever, dude. You're the one who buys the replacements."

Cisco rolls his eyes and plops the sucker back into his mouth, his sticky plump lips closing around it. Barry's never been more grateful that Cisco wants nothing to do with him in this mood.

He bites back a moan but Frost isn't so polite as to do the same internally. It goes straight to his groin and he grabs his bag to cover it, eager to get out of the building no matter how long he'll be waiting outside. No people would be for the best. Limiting it to them as the duo that he can't avoid will have to do.

.-

Entering the Uber, he presses himself into the leather seat and breaths a short-lived sigh of relief.

_You don't __**have**__ to wait. Bet you the driver won't care, not if you slip him a generous tip. Just slide that long-fingered hand of yours into your-_

"God, please _don't_," he says out loud, voice gruff and indecent to his own ears. Fuck. What will the driver think? He'd blush but he's pretty sure all his blood is heading to his cock. He clenches his hands again, this time so tight his nails dig in, blunt as they are. The discomfort is something to focus on other than his raging erection that begs to be grabbed. _Just please, Frost, stop begging too_, he thinks, wishing she could hear that.

_You're no fun, Barry Allen. If it were me..._

There's a lurch in his stomach and he can't tell for a moment if Frost is taking control. He loosens and clenches his hand again, relieved he's still able to.

"No, no, no... Hmpf," he chokes out as there's a flood of impatience hitting him and he feels extra flushed, painfully hot. Her emotions are spilling over and adding to his. His whole body throbs and he writhes around the seatbelt, the contact where it rests over his torso and waist too much.

He spies the driver eyeing him in the rear-view mirror.

"Are you talking to me?" the guy asks warily.

"No! No. Uh, Bluetooth headset." Barry says motioning to his ear vaguely. "Like, err... nano Bluetooth, barely there. Cutting edge. It's coming s-soon. Are we nearly there?" Barry asks. Adding a last bit of "_Please_" that he all but whines by accident, before descending into heavy breaths.

The driver doesn't question his BS excuse but he looks at least marginally disturbed by Barry's behavior. Barry doesn't blame him but he also doesn't care at this point. He just needs to get through his front door without doing anything that would be especially ill-advised for someone who works for CCPD.

The last few minutes of the drive are no less excruciating. The one mercy is how Frost remains blissfully silent for the rest of the ride. Barry runs up the stairs to his apartment as fast as he's ever done without his speed. That's only half the reason he's so out of breath once he closes his front door, leaning against it for support now he's safely on the other side.

Barry goes to pour out a glass of his special protein shake with shaky hands. He's in control. He doesn't have to do anything.

Frost disagrees immediately. _Why'd you come home early if you weren't planning on doing anything about it? You want to, I want to. Perfect opportunity. What more do you need, Barry White playing in the background? _she scoffs.

He continues to drink from the beaker.

_So, where do you keep your lube? Bet it's top drawer. Ready and waiting. Got any fun toys in there?_

He takes small sips, focusing on swallowing it down step by step as if he can fill himself up and thereby zone out of the other sensations he could be feeling.

_How many times a day does a speedster jack off - overdue much? Will you squirt everywhere the second you touch yourself? Is that why you don't want me to see, too embarrassed. Don't be. What's not to like when you're this hot and I get to feel it too. I want to come_ _just as much as you do._

He pauses, places the shake down. He _is_ too hot and he can actually do something about it now he's out of sight – he strips off his jacket and then his t-shirt. Flesh exposed to the chill of the aircon that's running.

_That's more like it, _Frost says. He'd expect it to be snarkier but it comes out inexplicably breathy for someone who isn't technically breathing.

He ignores Frost and walks to his room. Barry stands in the doorway, trying to focus on not touching himself and failing miserably. He starts taking off his chinos – just to get comfortable, he justifies - intending to put on some sweats but the brush of fabric on his cock as he removes them makes him stop. Every nerve feels on fire. It's not simply how horny he is without being able to get himself off for so long. He aches with the desire to use his speed too. That combination is what is driving him nuts. He wants it all _now_, the heady rush he knows so well as he comes ragged with the Speedforce tracing within.

_What does it feel like, Barry, when you're all lubed up and slick under your hand? Do you go slow or fast? Or ultra fast? Guess it's a sad day if that's your choice, no speed advantage today._

"Stop talking."

He's panting now, his chinos around his feet, clad only in his boxers. He had a plan to put on sweats but he can't move to do that. If he moves at all he knows what he'll do.

_Want to know who I think about...maybe we've got someone in common. I've even thought about you, 'warming me up'. You'd like that right now, wouldn't you? To get your dick wet on my cold cunt. Oh! OH, __**Barry**__! _she says with a low hearty laugh. Her exaggerated moaning to go with it mocks him but it's still effective in turning him on, his dick twitching against the thin layer remaining as a barrier. Her sounds morph into something much less feigned as she feels that effect. It's the last straw.

He stumbles to his drawer, kicking off his pants and pulling his underwear down in a rush. Squeezing out the cool lube on his hard-on puts him further on edge, the sensation close to what Frost described. Her on top of him is too easy to picture as he lays back on the bed and takes himself in hand, jerking up and down frantically, while she makes appreciative noises in response.

Each moan from her spurs him on faster and she seems to sense it, though he doesn't think it's faked, just as good for her as it is for him.

_Mmm, fuck yes, keep going. Faster._

No matter how much he pumps up and down, it's not enough, achingly slow without his powers. He needs more. _They _need more or his body is going to tremble on the edge of climax without the release it's been yearning for.

_Do it._

Activating his powers, he gets a spurt of speed that's almost enough to satisfy until the jarring coldness flashes across him too. The kickback of pain from the clash of powers drives him over the edge and he grunts as he comes thickly over his chest.

Barry spreads his arms and legs out over the sheets, relishing the softness on his sensitized skin and the loose-limbed feeling he has for the moment.

_Damn is it good to be a speedster_, Frost pipes up with, the most relaxed he's ever heard, her drawl almost lazy. _We can do that again in like a few minutes tops, right?_

"Sure, whatever."

He'd probably agree to just about anything in this blissed-out interlude but he could totally do with _at least_ another round of that and he can't find it in him to be shy about it anymore.


	2. Chapter 2

Additional tags/warnings - sex toys (anal plug, fleshlight)

**-Chapter 2-**

It had been two and a half weeks and there was still no end in sight to Frost being in his head. Whatever embarrassment he'd originally had with Frost and his sexual appetites was long gone.

Still, he was trying to keep the occurrences to a minimum; he didn't want to get too focused on it and how good it felt to combine the pain of ice and lightning. Plus, if he did any lasting damage to himself with it somehow that would be pretty awkward to explain... Soon enough that wouldn't be an option anymore and it wouldn't be helpful to be so attached to the fantasy then.

They made it into a competition of who could hold out longest. Frost didn't think it made any sense but she was competitive enough to go along with it anyway. So far she'd been the one to call time-out every single time. This time, however, she was holding out better than him.

"I need to go check on some, um, samples in my lab. Mold samples I've been culturing. For a case. Time-sensitive. I'll, you know...I'll be a while," Barry claims to the team after lunch. Luckily no one was really paying attention, but Barry hadn't stuck around to have it questioned anyway.

_Could you be any more transparent?_ Frost snarks as Barry came to a stop in his bedroom with a slight slide across the floorboards.

"Thought you'd be happy you won," Barry grumbles lightly as he finished unbuttoning his shirt. Pulling his t-shirt off, now all he had left to divulge himself of were his pants and underwear. As he unbuckled his belt he felt a flush of excitement perk his dick up. Finally, they were alone and he was aching to touch himself. He didn't care he'd lost, he only wanted the sweet relief of getting off. He was about to push his briefs down and free himself when Frost piped up and he felt resistance to his action, his body not complying with his wishes.

_Stop right there, mister._

He groans in frustration. God, how he ached. What was it now? He'd thought Frost would be fully on board with this like every other time.

_Winners choice. You got to do whatever you wanted every time you won so don't I get to drive now._

"Fine, whatever. Just do it, I can't take waiting any longer."

Frost chuckles but this time the throaty laugh comes from his lips which is unnerving. It was a strange sensation letting her take over. An almost floaty feeling of not being in control, detached from his body but completely aware of what she was doing.

As Frost shimmies out of his briefs and gives an experimental squeeze on his hard-on he realizes the benefit to this scenario. Her hand on his dick is practically like another person doing it to him because he doesn't know what to expect next. That only excites him further and he feels the grin on their face in response.

"So you like me in control, huh? Just you wait."

Frost sits down stark naked on his bed and starts rummaging through his bedside draw, which could feel like an overstep if not for the fact they've become so intimately acquainted lately. She quickly finds what she needs.

Frost pumps a couple of squirts of lube into her hand and settles back on his bed. She smooths it out between her palms, ironically warming it up. Barry mentally whines with need, wishing she'd get to it already. When she finally touches his dick it's a slow but sure move, her wrapping his long fingers around him dick and adjusting her grip until it feels good. Not good enough though for his liking and Frost tsk tsks in reply to his attempt to take back control of his hand. If she'd just move it...he yearns for that smooth slide up and down that he knows will build him up to an explosive peak.

Frost takes the hint at least and starts to jerk him off. Somehow it doesn't feel like his hand with the way she moves it. She doesn't stick to one pace or one grip, she keeps varying it, exploring the feel of him in her hand and how it makes his body react. His lips are permanently curled into a satisfied grin by her and she gasps with each new sensation, clearly enjoying herself. To him each pump on his cock is torturous. Good but not enough, not fast enough, not what he needs. He _needs_ to come.

He doesn't know if Frost senses his desperation, whether she's ignoring it or simply having too much fun. Whatever the answer, Frost has more in store he doesn't expect.

"Do you know what I'd do if I were here? Mmm. Bet you don't."

He thinks he doesn't care. He thinks wrong.

"If I was here in person, it wouldn't be your hand on your cock. Every time I do this," Frost illustrates with an extra tight fist around him, leisurely working his hand up and down and driving him to desperation for it to be faster, "imagine me sucking you off."

His dick twitches at the thought and Barry whines in response.

"But you probably wouldn't let me in on the action, would you Flash? As if you'd bring anyone else into this."

He can practically hear the pout. He doesn't know what to reply to the idea of him and Frost, because this worked out of necessity and now isn't the time to reconsider anything else. As she pumps up and down faster and he wills his body to buck up and meet that action, his brain is too fried to be able to be trusted to answer her.

Eventually, Frost works herself into a rhythm with it, one she gets behind just as much as him, letting a moan of her own out. He can feel the pressure building in his balls and eggs her on internally. _Please, Frost, more, please_. Begging her to keep it up and release them both from this agony of pleasure.

Instead Frost decides it's time to take a breather. Barry groans loudly.

_Frost!_

She's once again rooting round in his drawer and Barry's stomach flips a little in anticipation when he sees what toy she settles on.

"I want to feel full," she says as way of explanation, lubing up the butt plug good and proper.

_Have you done this before?_ he asks.

"Caity knows her anatomy real good, don't worry. Plenty of that rubbed off on me. I'll get back to rubbing off on you in no time."

Frost actually winks and Barry lets out a groan that's more exasperated than anything else.

Sure to her words, she doesn't waste any time before she's stroking around his asshole, spreading the lube around and finding where feels good. His body starts to feel amped up in a completely different way, though his neglected cock is nonetheless hard and leaking pre-cum all over the sheets. Before long she's worked him open enough to insert the toy, going agonizingly slow compared to how he would but he's patient, now is not the time to interfere. When it slides comfortably into place Frost pants in surprise.

_Frost, touch my dick. I will beg you if you want. __**Anything.**_

"Mhmm," she replies noncommittally with, too distracted, and then she shifts on the bed to his back and her weight is suddenly pushing the plug further into him.

_You like that? Good. _They're both in agreement as she gives in to the desire to press his ass into the bed and have it hit that sweet spot inside. Barry groans at the same time as she moans. But she stops. Again.

_Frost_, he whines again.

"Hey, you want it to be good, right? Trust me."

She shifts the butt plug more as she gets up and he feels her bite his lip, holding back on that desire to go with it and forget whatever else they could do. If she took him in hand, that feeling and a few more of those presses into the mattress and he could be coming all over himself. As it is he wonders if she moves about more than necessary just to feel that tease of it inside.

Leaning over into the draw she plucks out his fleshlight in record time, knowing what she's looking for since he used it a few times before while they were like this. Barry has a sudden flash forward to what her plan must be. He's worked up enough as it is but suddenly he's eager for what's in store too.

Frost pumps a lot of lube into the toy, probably too much, but Barry doesn't care. He just wants it on his dick ASAP. To buck up into it and then buck back down onto the plug, a see-saw of sensation.

Frost has the same thing in mind. This time she doesn't bother warming the lube and he gasps at the cool sheath fitting over him, still so good. Part of him can almost imagine it as her cool pussy. Frost hasn't been shy about talking that up during their sessions and he doesn't think he can stop himself thinking of that anytime a cool touch crops up.

He's so close, he can feel it but Frost is sliding it up and down slowly again and barely pressing into the mattress. He doesn't know why she's so restrained unless she wants to prolong it.

"Ooooh, that's _goood,_" Frost exclaims as she pushes back onto the plug.

"I'd ride you so hard, you'd like that, wouldn't you," The words come out a touch strangled but confidently said as she thrusts into the fleshlight,.

_Yes, yes! Faster Frost, __**please**__._

"Maybe one day you'll really let me, hmm," she says as she teases fucking the toy faster briefly before relenting and going back to more leisurely, as if she weren't as horny as him and in as much need of release.

He'd almost consider it evil but he knows the appeal of taking your time. The problem is he rarely has that patience anymore as a speedster and it takes someone else to get him to accept it's worthwhile. He 100% knows it will be good, more than good, but it's still hard when he's harder than ever and leaking pathetically into the sleeve when what he _really wants _is to spill into it with a final forceful thrust he's being denied.

_Frost. Please._ He's almost begging. Does he actually need to beg to get her to push them past this edge? When she halts at the ragged almost silence he realizes she's waiting for an answer.

_I don't think Cait would be so good with that. _He isn't sure what Cait would think of _this_ either, weird as it is for him to be doing anything sexual with Frost despite the fact she is in his head. It's still her body, Caitlin's body, that Frost talks up, taunts and teases him with the idea of. He feels vaguely guilty as it is that he's crossing a line.

Frost smirks with his face and he has a sinking feeling. What does she think is so amusing?

"You'd be surprised," she says between very definitive and distracting thrusts into the fleshlight, "I've only been with one man since I've been around. Can you guess who? Ungh," she ends with another fuck into the delighting folds of the toy.

Frost keeps up the pace like that and it's _just_ right. Working his dick into the fleshlight and the needy push back into the bed pressing the plug blindingly into his prostate. He's _so _close to coming again. His brain isn't working at its best but he thinks he knows what she's implying. He doesn't want to think it though, some possessive streak twisting at the revelation. _Can she mean __**him**__?_

He both hates the idea and wants it to be true.

"I see her dreams, she sees mine," Frost replies breathily, as she speeds up her thrusts deliciously too. It's what he's wanted but now he's set on edge by her words just as much as her actions. He's going to cum but it's a question of what to.

"Caitlin's had a taste of what you'd be like, more or less. A little rougher maybe. Don't you ever think about what Caity would be like? Those pink lips wrapped around your long cock -

He can't take it anymore, he breaks through in control without meaning to, taking over from Frost with the singular need to buck up into the warmed simulacrum of a cunt over and over. Of who it's meant to be he's not sure. Frost, Cait. Whoever, he wants it bad and he can't get _that_ but this feeling he can keep going. Reality and fantasy, memories and possibilities blur together dizzyingly as he holds onto the thought of her want for him. He just wants to fuck and feel and imagine it's true like he wants so bad.

Frost is there with him mentally at least, urging him on with stunted guttural words and indecent noises in reaction to each movement that spur him faster still. Her desperation to push down deeper onto the butt plug doesn't war with his desires at this stage. Their total agreement and working in tandem is a heady combination as the pleasure in his body spirals towards climax. It feels amazing and he wants it to last but he keeps going until his will to resist breaks and he spurts hard into the silicone sleeve several times, left panting and empty.


End file.
